Descriptive Epi

Question 1

Active surveillance

Answer 1

Going into community to search for new disease/condition cases

Question 2

Syndromic Surveillance

Answer 2

A system that looks for pre-defined signs/symptoms of patients

Question 3

Most important thing to define in Epi

Answer 3

“Case” definition… what it is

Question 4

Epidemic

Answer 4

Occurrence of disease clearly in excess of normal expectancy
Community/period clearly defined

Question 5

Outbreak

Answer 5

Epidemic limited to a localized increase

Interchanged with “cluster”

Question 6

Endemic

Answer 6

The constant presence of a disease within a given area of population in excess of normal levels elsewhere

Question 7

Pandemic

Answer 7

A widespread epidemic involving a large number of people

Question 8

Common or point source

Answer 8

Not person to person (Grandmas meatloaf)

One main area of peak in the graph

Question 9

Propagated source

Answer 9

Person-to-person spread (several peaks in graph)

Question 10

Calculation of a disease rate to compare

Answer 10

of events / and equal # of person years

Question 11

Incidence

Answer 11

New cases of disease 
# new cases of disease / # of possible people at risk for the disease 
Remember to remove those who already have disease

Question 12

Prevalence

Answer 12

Existing cases of disease + new cases of disease 
# of existing cases of a disease / # of persons in population ;plp

Question 13

Four Categories of 2x2 table

Answer 13

Exposed vs Non-exposed
Disease vs Non-diseased
Basically… what was exposed (category) and yes/no if they got the disease or incident

Question 14

Risk Ratio (RR)

Answer 14

A / (A+B) : Exposed Risk
C/ (C+D) : Non-Exposed Risk
1.0000001 - 1.99999 = use decimal to show increase 1-99% increase

Question 15

Incidence Risk (IR)

Answer 15

Same as RR

Question 16

Odds Ratio

Answer 16

“times control” for interpretation
2.0 to infinity
2x 3x … greater odds to do something than comparator group

Question 17

Absolutely Risk Reduction (ARR)

Answer 17

Simple “absolute” difference in risks

Exposed - unexposed (ramipril example)

Question 18

Relative Risk Reduction (RRR)

Answer 18

(ARR) / R(unexposed)

Absolutely difference / placebo group percentage

Question 19

Number Needed to Treat (NNT)

Answer 19

1 / Absolutely Risk Reduction
Ramipril example: 1 / .038 = 26.32 (27 patients)
Number of whole patients needed to be treated to experience the studied event outcome (can be beneficial or harmful)

Question 20

Odds Ratio (OR)

Answer 20

Odds of exposure (cases) / Odds of exposure (control)

A/C) / (B/D

Question 21

Passive Surveilance

Answer 21

Relies on healthcare system to follow regulations on required reportable diseases/conditions